1. Field of the Invention
The present invention relates to an ink-jet printer, and a recording method using the same, an ink cartridge used in the same, and ink-jet printer ink.
2. Description of the Related Art
Recently, the technical progress of a printer, especially, an ink-jet printer as a data output apparatus is remarkable with the wide use of a personal computer. Various type of ink-jet printers are marketed for various applications such as photograph quality and high-speed print like a laser printer.
Color ink cartridges and a black ink cartridge are generally prepared for the ink-jet printer. Thus, the print of a color image is possible, in addition to a monochromatic color print. In case of color print, the inks of three colors such as cyan, magenta and yellow are used as the color inks. Moreover, there is a case that ink of a light color is prepared in addition to these color inks. In any case, a plurality of color inks are generally piled, or layered, for color expression.
By the way, the demand of the bidirectional print has been rising recently for the improvement of the print speed. In a conventional ink-jet printer, a unidirectional print is adopted in which an ink-jet head is moved in a unidirection while ejecting ink drops. On the other hand, in the bidirectional print, the ejection of ink drops is carried out in a going way of the ink-jet head in a main scanning direction and a returning way in a direction opposite to the main scanning direction. In this case, almost twice of the print speed in the unidirectional print can be achieved in the bidirectional print.
However, the ink-jet head generally has the structure in which the ejecting nozzles of the cartridges of the colors of black, cyan, magenta and yellow are aligned on a line. Therefore, when the printer layers of two or more colors, a coloring difference develops, depending on whether the print head is traveling in the going way or the returning way.
For example, it is supposed an ink set is comprised of black and three colors of cyan, magenta and yellow. In this case, blue color is formed by adhesion of an ink drop of cyan and an ink drop of magenta. During operation, while the print head travels in the going direction, magenta contacts the paper prior to cyan. At the contact point, magenta, rather than cyan, primarily adheres to the paper. For this reason, the ink of cyan goes around the ink drop of magenta and then soaks into the paper sheet.
On the other hand, when creating a blue color in the returning way, the order of the ejection nozzles is opposite so that the ink drops are ejected in order of cyan and magenta. In this case, the ink drop of cyan is adhered on the surface of the paper sheet prior to the ink drop of magenta and stays on the surface of the paper sheet. For this reason, the ink of magenta goes around the ink drop of magenta and then soaks into the paper sheet.
In the two cases described above, the ink adhered earlier has the tendency to color strongly, creating what is referenced below as a xe2x80x9ccoloring difference.xe2x80x9d As a result, in the going way, the color of magenta is emphasized, and in the returning way, the color of cyan is emphasized.
Moreover, the coloring difference is more conspicuous in a print paper sheet with large quality deviation rather than glossy fine paper sheet in which the ink absorption is uniform and quick. The elimination of the coloring difference in the bidirectional print is demanded in the business use in addition to the high-speed print and the large -amount print.
In order to improve the above-mentioned problem, an ink-jet printer is proposed in which the inks are arranged in order of the colors of cyan, magenta, yellow, yellow, magenta, and cyan to the direction of the movement of the ink-jet head. In this conventional ink-jet printer, the ejection order of the inks is made identical in the going way and the returning way. However, the ink cartridges for the multiple colors have to be arranged symmetrically with respect of the center of a row of ink cartridges, like the described above. Therefore, the ink-jet head becomes large-sized, compared with the conventional ink-jet head that the ink-jet cartridges of cyan, magenta and yellow are arranged, resulting in cost-up.
Also, an ink-jet printer is disclosed in Japanese Laid Open Patent application (JP-A-Heisei 4-185452). In this reference, a printing operation is carried out in a going way, an ink-jet head is rotated by 180 degrees, and then the print operation is carried out in a returning way. In this method, the overall print time and structural size both increase.
As described above, various proposals were made for elimination of the coloring difference in the bidirectional print. However, because the structure of the printer is changed or the ejection method of inks is changed, it is difficult to incorporate the proposals in the existing printer.
In conjunction with the above description, ink and a recording method using it are disclosed in Japanese Laid Open Patent application (JP-A-Heisei 6-157959). In this reference, the ink is comprised of water, coloring material dispersed or soluble in the water, wetting agent, and 2-ethyl-1,3-hexanediol. A recording operation is carried out on a paper sheet with Steckigt sizing degree of 3 sec. or more with the ink.
Also, ink and a recording method are disclosed in Japanese Laid Open Patent Application (JP-A-Heisei 8-193177). The ink is comprised of (A) coloring agent, (B) penetrant selected from three of Monohydric alcohol, derivative of Polyhydric alcohol, and interfacial active agent equal to or less than micell concentration, (C) alginate, (D) at least one kind of interfacial active agent selected from fluoric interfacial active agent and silicon interfacial active agent with a value of expanse T shown below, (E) wetting agent and (F) water.
T=D/D0xc3x97100
where D is the diameter of a liquid drop of 0.05 wt % dropped on a paper sheet after 2 minutes, and D0 is the diameter of an ion exchange water drop dropped on a paper sheet after 2 minutes.
Also, ink and a recording method are disclosed in Japanese Laid Open Patent application (JP-A-Heisei 11-207999). In a recording head, a plurality of nozzles to eject inks are arranged to the direction sending a printed medium as a sub scanning direction. Also, a group of the nozzles is arranged in a print direction as a main scanning direction on the printed medium. The sub scanning is carried out between a going way and a returning way. For color mixture print, first color ink is ejected and then second color ink is ejected and a quantity of the second color ink is less than a quantity of the first color ink. However, it is necessary to provide an additional function to control the ejection quantities of the color inks, resulting in cost-up.
Also, an ink-jet recording medium is disclosed in of Japanese Laid Open Patent Application (JP-P2000-238414A). The ink-jet recording medium contains cationic resin in a range of cationic strength of 2 to 8 m equivalence/g as cationic residue equal to or more than 3 mmol/m2. Also, the ink-jet recording medium has a transfer quantity of 30 ml/m2 of distilled water to the recording medium measured by a dynamic scan absorption meter in the contact time of 10 ms.
Therefore, an object of the present invention is to provide an ink-jet printer and a printing method, in which coloring difference in the bidirectional print can be eliminated without any additional structure and any control method.
Another object of the present invention is to provide an ink-jet printer and a printing method, in which high-speed bidirectional print is possible.
Still another object of the present invention is to provide an ink-jet printer ink cartridge and inks used in the above ink-jet printer and the printing method.
In an aspect of the present invention, an ink set is used in a bidirectional print, and each of first and second absorption quantity differences is equal to or less than 10 ml/m2 in a contact time of 10 msec. in a dynamic scanning absorption meter. The first absorption quantity difference indicates difference between a absorption quantity when a first ink of the ink set is applied on a paper sheet on which a second ink of the ink set is applied and which is used for a print operation, and a absorption quantity when the first ink is applied on the paper sheet on which no ink is applied. The second absorption quantity difference indicates difference between an absorption quantity when the second ink is applied on the paper sheet on which the first ink is applied, and an absorption quantity when the second ink is applied on the paper sheet on which no ink is applied.
It is desirable that a time period from when the first ink is applied to when the second ink is applied or a time period from when the second ink is applied to when the first ink is applied is equal to or less than 30 sec.
Also, the ink may be dye-based ink. The dye-based ink may contain at least one kind of direct dye and acid dye, and the direct dye contains one selected from the group consisting of CI. direct yellow, CI. direct blue, CI. direct red, and the acid dye contains one selected from the group consisting of CI. acid yellow, CI. acid blue, CI. acid red.
Also, the ink may be pigment ink. An coloring material is selected from the group consisting of inorganic pigment, and insoluble Azo pigment, soluble Azo pigment, Phthalocyan pigment, Isoindolinon pigment, Quinacridorine pigment and Perylene pigment.
In this case, the coloring material is in a range of 1 to 10 wt % of a solid component of the ink.
Also, the ink may include solvent selected from the group consisting of ion exchange water, Alkyl alcohol ether with 1 to 4 carbons such as Methanol, Ethanol, N-propanol, Isopropanol, N-butanol, Sec-butanol, Tert-butanol, and Isobutanol, Amid such as Dimethylholmiamid and Dimethylaccetamid, Ketone or Ketoalcohol such as Acetone and Diacetone alcohol, ether such as Tetrahydrofuran and Dioxane, polyalkylene glycol such as Polyethylene glycol, and Polypropylene glycol, Alkylene glycol containing Alkylene group with 2 to 6 carbons such as Ethylene glycol, Propylene Glycol, 1, 2, 6-hexanetriol, Thiodiglycol, and Hexylene Glycol, and Lower alkyl ether of Polyhydric alcohol such as Glycerin, Ethylene Glycol methyl ether, Diethylene glycol monomethyl (monoethyl) ether, and Triethylene glycol monomethyl (monoethyl) ether.
Also, the ink may include agent selected from the group consisting of dispersion agent, interfacial active agent, viscosity conditioner, surface tension conditioner, pH conditioner, oxidation inhibitor, mildewproof agent, and chelating agent.
In another aspect of the present invention, an ink cartridge is for an ink-jet printer, and the ink cartridge is filled with one of an ink set used in a bidirectional print. Each of first and second absorption quantity differences is equal to or less than 10 ml/m2 in a contact time of 10 msec. in a dynamic scanning absorption meter. The first absorption quantity difference indicates difference between a absorption quantity when a first ink of the ink set is applied on a paper sheet on which a second ink of the ink set is applied and which is used for a print operation, and an absorption quantity when the first ink is applied on the paper sheet on which no ink is applied. The second absorption quantity difference indicates difference between an absorption quantity when the second ink is applied on the paper sheet on which the first ink is applied, and an absorption quantity when the second ink is applied on the paper sheet on which no ink is applied.
It is desirable that a time period from when the first ink is applied to when the second ink is applied or a time period from when the second ink is applied to when the first ink is applied is equal to or less than 30 sec.
In still another aspect of the present invention, an ink-jet printer includes an ink-jet head with a plurality of ink cartridges, a drive section which drives the ink-jet head in a going way and a returning way; and a print control section which drives the ink-jet head based on print data such that ink drops are ejected from the plurality of ink cartridges. Each of the plurality of ink cartridges is filled with one of an ink set used in a bidirectional print, wherein each of first and second absorption quantity differences is equal to or less than 10 ml/m2 in a contact time of 10 msec. in a dynamic scanning absorption meter. The first absorption quantity difference indicates difference between a absorption quantity when a first ink of the ink set is applied on a paper sheet on which a second ink of the ink set is applied and which is used for a print operation, and an absorption quantity when the first ink is applied on the paper sheet on which no ink is applied. The second absorption quantity difference indicates difference between an absorption quantity when the second ink is applied on the paper sheet on which the first ink is applied, and an absorption quantity when the second ink is applied on the paper sheet on which no ink is applied.
It is desirable that a time period from when the first ink is applied to when the second ink is applied or a time period from when the second ink is applied to when the first ink is applied is equal to or less than 30 sec.
In still another aspect of the present invention, a method of printing data by an ink-jet printer may be achieved by driving an ink-jet head in a going way and a returning way, the ink-jet head with a plurality of ink cartridges; and by driving the ink-jet head based on print data such that ink drops are ejected from the plurality of ink cartridges. Each of the plurality of ink cartridges is filled with one of an ink set used in a bidirectional print, wherein each of first and second absorption quantity differences is equal to or less than 10 ml/m2 in a contact time of 10 msec. in a dynamic scanning absorption meter. The first absorption quantity difference indicates difference between a absorption quantity when a first ink of the ink set is applied on a paper sheet on which a second ink of the ink set is applied and which is used for a print operation, and a absorption quantity when the first ink is applied on the paper sheet on which no ink is applied. The second absorption quantity difference indicates difference between an absorption quantity when the second ink is applied on the paper sheet on which the first ink is applied, and an absorption quantity when the second ink is applied on the paper sheet on which no ink is applied.
It is desirable that a time period from when the first ink is applied to when the second ink is applied or a time period from when the second ink is applied to when the first ink is applied is equal to or less than 30 sec.